China Users Report WhatsApp Disruption Amid Censorship Fears

BEIJING — Users of WhatsApp in China are reporting widespread service disruptions amid fears that the popular messaging service may be blocked at least partially by Chinese authorities.

WhatsApp users on the mainland reported Tuesday on other social media platforms that the messaging app was inaccessible without virtual private network software used to circumvent China’s censorship apparatus, known colloquially as The Great Firewall.

It appeared that users in China could send texts over WhatsApp without VPNs but not images.

Chinese foreign ministry spokesman Lu Kang said he had no information on the issue when asked by reporters.

Facebook, which owns WhatsApp, did not immediately respond to a request for comment.

China blocked Telegram, another messaging service, in 2015 after it became a popular platform for activists and dissidents to share information.

A vigil for the Chinese dissident Liu Xiaobo in Hong Kong on Saturday. China’s censors blocked images of Mr. Liu and of people commemorating him.Credit Billy H.C. Kwok/Getty Images

BEIJING — It came as little surprise when, after the death of the dissident Liu Xiaobo last week, China’s vast army of censors kicked into overdrive as they scrubbed away the outpouring of grief on social media that followed.

The accounts of censorship have been mostly anecdotal. But systematic research from the Citizen Lab at the University of Toronto’s Munk School of Global Affairs shows that there was a “significant shift” in censorship techniques in the days after Mr. Liu’s death, particularly on WeChat, the popular messaging app from Tencent.

On WeChat, which has more than 768 million daily active users, the number of keyword combinations that were blocked greatly increased, according to the report that the Citizen Lab published on Sunday. Additions to the blacklist included general references to his death like “Xiaobo + died” in Chinese and in English, and even just his name “Liu Xiaobo,” effectively censoring any messages that mentioned him.

The Citizen Lab said it was also the first time that images were automatically filtered in private one-on-one chats on WeChat. Blocked images included photographs of Liu Xiaobo and of people commemorating him.

One of the distinguishing features of WeChat is that it does not notify users when their messages are blocked. The service also makes a distinction between accounts registered to phone numbers from mainland China and phone numbers from elsewhere.